package com.spark.sql

import org.apache.spark.sql.expressions.Window
import org.apache.spark.sql.{Column, DataFrame, SparkSession}

object Demo8Burks {
  def main(args: Array[String]): Unit = {
    val spark: SparkSession = SparkSession
      .builder()
      .appName("burk")
      .master("local")
      .config("spark.sql.shuffle.partitions", 1)
      .getOrCreate()
    import org.apache.spark.sql.functions._
    import spark.implicits._

    //读取数据
    val burksDF: DataFrame = spark
      .read
      .format("csv")
      .option("sep", ",")
      .schema("burk STRING,year STRING,tsl01 DOUBLE,tsl02 DOUBLE,tsl03 DOUBLE,tsl04 DOUBLE,tsl05 DOUBLE,tsl06 DOUBLE,tsl07 DOUBLE,tsl08 DOUBLE,tsl09 DOUBLE,tsl10 DOUBLE,tsl11 DOUBLE,tsl12 DOUBLE")
      .load("data/burks.txt")

    burksDF.show()

    /**
     * 1、统计每个公司每年按月累计收入  行转列 --> sum窗口函数
     * 输出结果
     * 公司代码,年度,月份,当月收入,累计收入
     */

    /**
     * sql
     */
    burksDF.createOrReplaceTempView("burks")

    spark.sql(
      """
        |select
        |burk,year,month,plc,
        |sum(plc) over(partition by burk,year order by month) as leiji
        | from (
        |select burk,year,month,plc
        |from burks
        |lateral view explode(map(1,tsl01,2,tsl02,3,tsl03,4,tsl04,5,tsl05,6,tsl06,7,tsl07,8,tsl08,9,tsl09,10,tsl10,11,tsl11,12,tsl12)) T as month,plc
        |) as a
        |
        |""".stripMargin)
    // .show(100)

    /**
     * DSL
     *
     */

    val m: Column = map(
      expr("1"), $"tsl01",
      expr("2"), $"tsl02",
      expr("3"), $"tsl03",
      expr("4"), $"tsl04",
      expr("5"), $"tsl05",
      expr("6"), $"tsl06",
      expr("7"), $"tsl07",
      expr("8"), $"tsl08",
      expr("9"), $"tsl09",
      expr("10"), $"tsl10",
      expr("11"), $"tsl11",
      expr("12"), $"tsl12"
    )

    burksDF
      //一行转换成多行
      .select($"burk", $"year", explode(m) as Array("month", "plc"))
      //计算按月累计
      .withColumn("leiji", sum($"plc") over Window.partitionBy($"burk", $"year").orderBy($"month"))
    //.show(100)


    /**
     * 2、统计每个公司当月比上年同期增长率  行转列 --> lag窗口函数
     * 公司代码,年度,月度,增长率（当月收入/上年当月收入 - 1）
     *
     *
     * coalesce: 返回第一个部位null的列
     *
     */

    burksDF
      //一行转换成多行
      .select($"burk", $"year", explode(m) as Array("month", "plc"))
      //取上年同期的收入
      .withColumn("last_plc", lag($"plc", 1) over Window.partitionBy($"burk", $"month").orderBy($"year"))
      //计算增长率
      //.withColumn("p", coalesce(round($"plc" / $"last_plc" - 1, 5), expr("1.0")))
      .withColumn("p", round($"plc" / $"last_plc" - 1, 5))
      .withColumn("p1", when($"p".isNotNull, $"p").otherwise(1.0))
      .show(100)
  }

}
